The Parkes Pulsar Timing Array project aims to make a direct detection of a gravitational wave background through the timing of millisecond pulsars. In this paper, the main requirements for that endeavour are described and recent and ongoing progress is outlined. We demonstrate that the timing properties of millisecond pulsars are adequate and that technological progress is timely to expect a successful detection of gravitational waves within a decade, or alternatively to rule out all current predictions for gravitational wave backgrounds formed by supermassive black-hole mergers.

The Parkes Observatory is part of the Australia Telescope which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. The authors acknowledges support from a WVEPSCoR research challenge grant held by the WVU Center for Astrophysics.